The effect of ofloxacin on the human corneal endothelium

Possible toxic effects of ofloxacin on human corneal endothelia were assessed by using electron microscopy and in vitro specular perfusion.

Five pairs of corneas [with one cornea of each pair receiving balanced salt solution (Endosol; Allergan, Irvine, CA, U.S.A.) and the other receiving Endosol with 10 micrograms/ml of ofloxacin] underwent perfusion for 3 h with corneal pachymetry every 15 min followed by tissue fixation. A mean corneal swelling rate was calculated from a first-order regression line fit for each of the five experiments. The swelling rates between groups was compared by-using a paired t test. Scanning and transmission electron micrographs were examined for cellular architecture. Another group of five pairs of corneas was perfused the same way with the only difference being a test dose of 30 micrograms/ml.

The mean swelling rate for corneas perfused with 10 micrograms/ml of ofloxacin of -3.5 microns/h was not significantly different from that of the Endosol-alone corneas at -3.0 microns/h (p = 0.71). The mean swelling rate for corneas perfused at 30 micrograms/ml of ofloxacin was -4.1 microns/h, not significantly different from Endosol-alone perfused corneas at -6.5 microns/h (p = 0.08). No consistent ultrastructural changes could be attributed to exposure to 10 or 30 micrograms/ml of ofloxacin.

Human corneal endothelium can be exposed to ofloxacin at a dose of 30 micrograms/ml for a period of 3 h without adverse ultrastructural or physiologic side effects.